Light-emitting diode package and manufacturing method thereof

ABSTRACT

An LED package is provided. The LED package comprises a metal plate, circuit patterns, and an LED. The metal plate comprises grooves. The insulating layer is formed on the metal plate. The circuit patterns are formed on the insulating layer. The LED is electrically connected with the circuit pattern on the insulating layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/910,174, filed Sep. 28, 2007, which is the U.S. national stageapplication of International Patent Application No. PCT/KR2007/001020,filed Feb. 28, 2007, which claims priority to Korean Patent ApplicationNo. 10-2006-0020305, filed Mar. 3, 2006, all of which are incorporatedherein by reference in their entirety.

TECHNICAL FIELD

The embodiment of the present invention relates to a light-emittingdiode (LED) package and a manufacturing method thereof.

BACKGROUND ART

An LED package includes an LED and a printed circuit board (PCB) forapplying a driving signal to the LED and supporting the LED.

The LED is a device for converting electrical energy into light. Heat isgenerated while the electrical energy is converted into light. The abovegenerated heat reduces a driving characteristic of the LED.

Therefore, the heat generated at the LED needs to be effectively suck.

Meanwhile, an LED package may attach a heatsink member to a PCB to allowheat generated at the LED to be swiftly sunk.

However, in the case where the heatsink member is attached, a process iscomplicated and costs increase.

Also, light emitted from the LED is blocked depending on an attachingposition of the heatsink member, so that light emitting efficiency of anLED chip is reduced.

DETAILED DISCLOSURE Technical Problem

An embodiment of the present invention provides an LED package and amanufacturing method, allowing heat generated from an LED chip to beeffectively sunk.

An embodiment of the present invention provides an LED package and amanufacturing method, capable of preventing light emitting efficiencyfrom being reduced while allowing heat generated from an LED chip to beeffectively sunk.

Technical Solution

An embodiment of the present invention provides a light-emitting diodepackage comprising: a metal plate having grooves; an insulating layer onthe metal plate; circuit patterns on the insulating layer; and alight-emitting diode electrically connected with the circuit pattern onthe insulating layer.

An embodiment of the present invention provides a method formanufacturing a light-emitting diode package, the method comprising:preparing a metal core printed circuit board; selectively removing ametal plate contained in the metal core printed circuit board to formgrooves; and mounting a light-emitting diode on the metal core printedcircuit board.

An embodiment of the present invention provides an apparatus comprising:a metal plate having grooves; an insulating layer on a metal plate; acircuit pattern on the insulating layer; and an electronic deviceelectrically connected with the circuit pattern on the insulating layer.

ADVANTAGEOUS EFFECTS

An LED package according to an embodiment of the present invention canallow heat to be effectively sunk.

An LED package according to an embodiment of the present invention canallow heat to be effectively sunk without reducing light emittingefficiency of an LED chip.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 to 4 are views explaining a method for manufacturing an LEDpackage according to first embodiment of the present invention;

FIG. 5 is a view explaining an LED package according to secondembodiment of the present invention; and

FIG. 6 is a view explaining an LED package according to third embodimentof the present invention.

MODE FOR INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. It will also be understood that when an element is referred toas being on or under another element, it can be directly on the otherelement, or intervening elements may also be present.

FIGS. 1 to 4 are views explaining a method for manufacturing an LEDpackage according to first embodiment of the present invention. FIGS. 1and 2 are views exemplarily illustrate a process for forming a metalcore printed circuit board (MCPCB).

A method for maximizing a heatsink effect of the MCPCB will be describedaccording to an embodiment of the present invention.

Referring to FIG. 1, an insulating layer 11 is formed on a metal plate10.

The insulating layer 11 can be a resin layer. FR4 resin layer, which isa glass epoxy-based material, can be used as the resin layer, forexample.

The metal plate 10 is formed to have thickness of several to several tenmillimeters using metal such as Al and Au having excellent thermalconductivity, and serves as a heatsink.

The insulating layer 11 is formed using an FR4 resin layer having highmechanical strength and excellent durability, so that it is littledeformed by heat even when it has a thin thickness, and havingadhesiveness, so that it is suitable for forming a layer.

Meanwhile, the insulating layer 11 can be formed on an upper surface ofthe metal plate 10 using a press or a thermal compressing jig. Theinsulating layer 11 can adhere on the metal plate 10 using heat appliedby a press or the thermal compressing jig.

Referring to FIG. 2, circuit patterns 12 are formed on the insulatinglayer 11.

The circuit patterns 12 are formed of metal such as Cu. The circuitpatterns 12 can be formed using process technology for forming asemiconductor circuit, such as photolithography, metallization, andetching.

Through the above-process, an MCPCB where the circuit patterns 12 havebeen formed is prepared as illustrated in FIGS. 1 and 2.

Referring to FIG. 3, a reflective layer 13 is selectively formed on theinsulating layer 11.

The reflective layer 13 can be formed on a portion of the insulatinglayer 11 where the circuit patterns 12 have not been formed using acoating method.

The reflective layer 13 is designed for increasing brightness of lightemitted from an LED chip, and appropriately formed on the portion of theinsulating layer 11 with consideration of a region where the LED chip ismounted and a region where the circuit pattern 12 is formed.

The reflective layer 13 can be used a white resin formed by mixing TiO₂and a resin as a primary component with at least one of CaCO₃, BaSO₄,and ZnO. Of course, the reflective layer 13 can be formed using whitepigment besides the white resin.

Though the reflective layer 13 is not formed between the circuitpatterns 12 in FIG. 3, the reflective layer 13 can be formed between thecircuit patterns 12 depending on selection.

Screen printing, not dispensing, which uses air pressure is used to formthe white resin in the form of the reflective layer 13.

The screen printing can coat the white resin over a large area for arelatively short period of time compared to the dispensing that uses airpressure, and requires low costs.

According to the screen printing, a screen mask having a thickness of 50on is formed on the circuit patterns 12, and portions that exclude thescreen mask are filled with a white resin using a squeeze.

In detail, the squeeze moves in a predetermined direction along an uppersurface of the screen mask while it rubs a liquid white resin, so thatthe portions that exclude the screen mask arc filled with the liquidwhite resin.

The portions that exclude the screen mask are filled with the liquidwhite resin so that a surface of the white resin become planarized to beequal to an upper surface of the screen mask. Also, the screen mask isremoved, and annealing is performed at a predetermined temperature tocure the white resin.

Referring to FIG. 4, after the reflective layer 13 formed of the whiteresin is formed, an LED chip 14 is mounted on the MCPCB.

In detail, the LED chip 14 is mounted on the circuit pattern 12, and theLED chip 14 is electrically connected to the circuit patterns 12 usingwires 15. Also, a molding portion 16 is formed to cover the LED chip 14and the wires 15.

The LED chip 14 can be formed on the insulating layer 11 or thereflective layer 13.

Meanwhile, the LED chip 14 can be mounted on a silicon optical bench(SiOB) through flip-bonding. The SiOB on which the LED chip 14 has beenmounted through flip-bonding is mounted on the insulating layer 11 usingpaste having thermal conductivity, so that the LED chip 14 can beelectrically connected to the circuit patterns 12 using lead frames.

After the LED chip 14 is mounted on the MCPCB, the metal plate 10, theinsulating layer 11, and the reflective layer 13 are selectively removedto form a plurality of grooves 17 in an upper surface of the metal plate10.

Since portions of the insulating layer 11 and the reflective layer 13are removed from the upper surface of the groove 17, bottom surfaces andlateral sides of the grooves 17 are exposed to air. Therefore, heatsinkeffect of the metal plate 10 can be maximized.

Meanwhile, the LED chip 14 may be mounted on the MCPCB after the grooves17 are formed.

Here, the plurality of grooves 17 can be formed through a mechanicalmethod using a drilling machine or a milling machine, or a chemicalmethod using etching.

Therefore, according to an LED package of the above embodiment, asurface area of the metal plate 10 required for heatsink is widened bythe plurality of grooves 17, so that heat generated from the LED chip 14can be effectively sunk. Therefore, thermal reliability of the LED chip14 can be improved and thus performance of the LED chip 14 can beimproved.

FIG. 5 is a view explaining an LED package according to secondembodiment of the present invention.

Unlike the LED package of FIG. 4, the LED package illustrated in FIG. 5provides a plurality of grooves 17 formed in a lower surface of themetal plate.

Therefore, an area on which the reflective layer 13 has been formedincreases, so that light efficiency can be improved even more and thenumber of the grooves 17 increases to maximize a heatsink effect.

FIG. 6 is a view explaining an LED package according to third embodimentof the present invention.

Unlike the LED package of FIGS. 4 and 5, the LED package illustrated inFIG. 6 provides a plurality of grooves 17 formed in an upper surface anda lower surface of the metal plate 10.

Therefore, a heatsink effect by the plurality of grooves 17 can bemaximized.

Meanwhile, the grooves 17 in the upper surface of the metal plate 10 andthe grooves 17 in the lower surface of the metal plate 10 are formedsuch that their positions are different from each other. That is, thegroove 17 is not formed in a lower portion of the groove 17 formed inthe upper surface of the metal plate, and the groove 17 is formed in alower portion of the upper surface of the metal plate where groove 17has not been formed.

In other words, the groove 17 formed in the upper surface of the metalplate, and the groove 17 formed in the lower surface of the metal plateare not located on the same line.

Accordingly, mechanical strength of the metal plate 10 can bemaintained.

Though description has been made for an embodiment where an LED packageon which the LED chip has been mounted, the present invention can beapplied to an MCPCB on which various electronic devices such as anintegrated circuit (IC) and a resistor are mounted.

INDUSTRIAL APPLICABILITY

The embodiment of the present invention can be applied to a circuitboard on which electronic devices have been mounted.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present invention. Thus,it is intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A lighting apparatus, comprising: a printed circuit board includingan upper principal surface and a lower principal surface, wherein theprinted circuit board includes circuit patterns on the upper principalsurface; and a light emitting device disposed on the upper principalsurface of the printed circuit board and electrically connected with thecircuit patterns; wherein the printed circuit board includes removedportions spaced from the circuit patterns.
 2. The lighting apparatusaccording to claim 1, wherein the printed circuit board includes a metalplate, an insulating layer on the metal plate, and the circuit patternson the insulating layer.
 3. The lighting apparatus according to claim 2,wherein the printed circuit board further includes a reflective layer onthe insulating layer.
 4. The lighting apparatus according to claim 1,wherein the printed circuit board further includes a reflective layer onthe upper principal surface, and wherein the reflective layer has athickness greater than a thickness of the circuit patterns.
 5. Thelighting apparatus according to claim 1, wherein the removed portionsinclude recesses.
 6. The lighting apparatus according to claim 1,wherein the lower principal surface of the printed circuit boardincludes recesses.
 7. The lighting apparatus according to claim 1,wherein the light emitting device includes a light emitting diode chip.8. The lighting apparatus according to claim 7, wherein the lightemitting device further includes a molding portion for protecting atleast a portion of the circuit patterns and the light emitting diodechip.
 9. The lighting apparatus according to claim 7, wherein at leastone of the removed portions has a width narrower than the light emittingdiode chip.
 10. The lighting apparatus according to claim 1, wherein atleast one of the removed portions has a width narrower than the lightemitting device.
 11. The lighting apparatus according to claim 1,wherein the light emitting device is disposed outside of the removedportions.
 12. A lighting apparatus, comprising: a printed circuit boardincluding an upper principal surface and a lower principal surface,wherein the printed circuit board includes circuit patterns on the upperprincipal surface; and a light emitting device disposed on the upperprincipal surface of the printed circuit board, wherein the circuitpatterns include a first circuit pattern and a second circuit pattern,wherein the first circuit pattern is electrically separated from thesecond circuit pattern, wherein the light emitting device includes alight emitting diode chip on the second circuit pattern, and wherein thelight emitting diode chip is electrically connected with the firstcircuit pattern.
 13. The lighting apparatus according to claim 11,further comprising a resin layer on the printed circuit board.
 14. Thelighting apparatus according to claim 13, wherein the resin layer is incontact with a lateral surface of the first circuit pattern.
 15. Thelighting apparatus according to claim 11, wherein the light emittingdevice further includes a molding portion for protecting at least aportion of the circuit patterns and the light emitting diode chip. 16.The lighting apparatus according to claim 15, wherein the moldingportion is disposed between the first circuit pattern and the secondcircuit pattern.
 17. The lighting apparatus according to claim 15,wherein the molding portion includes a hemisphere shape.
 18. Thelighting apparatus according to claim 12, wherein the printed circuitboard further includes removed portions spaced from the second circuitpattern.